Magnetic field effects on the conductivity of organic bipolar and unipolar devices at room temperature

Magnetic field effects on the conductivity of different types of organic devices: undoped and dye doped aluminium (III) 8-hydroxyquinoline (Alq(3))-based organic light emitting diodes (OLEDs), electron-only Alq(3)-based diodes, and a hole-only N,N`-diphenyl-N,N`-bis(1-naphthyl)1,1`-biphenyl-4,4`-diamine (alpha-NPD)-based diode were studied at room temperature. Only negative magnetoresistance (MR) was observed for the Alq(3)-based devices. The addition of a rubrene dye in Alq(3)-based OLEDs quenches the MR by a factor of 5. The alpha-NPD hole-only device showed only positive MR. Our results are discussed with respect to the actual models for MR in organic semiconductors. Our results are in good agreement with the bipolaron model. (C) 2009 Elsevier B.V. All rights reserved.

Novel Treatment Immediately after Myelomeningocele Repair Applying Low-Level Laser Therapy in Newborns: A Pilot Study

Background/Aims: The use of low-level laser therapy (LLLT) in neurosurgery is still hardly disseminated and there are situations in which the effects of this therapeutic tool would be extremely relevant in this medical field. The aim of the present study is to analyze the effect of LLLT on tissue repair after the corrective surgical incision in neonates with myelomeningocele, in an attempt to diminish the incidence of postoperative dehiscences following surgical repair performed immediately after birth. Materials and Methods: Prospective pilot study with 13 patients submitted to surgery at birth who received adjuvant treatment with LLLT (group A). A diode laser CW, lambda = 685 nm, p = 21 mW, was applied punctually along the surgical incision, with 0.19 J delivered per point, accounting for a total of 4-10 J delivered energy per patient, according to the surgical wound area and then compared with the results obtained in 23 patients who underwent surgery without laser therapy (group B). Results: This pilot study disclosed a significant decline in dehiscences of the surgical wounds in neonates who were submitted to LLLT (7.69 vs. 17.39%). Conclusion: This new adjuvant therapeutic modality with LLLT aided the healing of surgical wounds, preventing morbidities, as well as shortening the period of hospital stay, which implies a reduction of costs for patients and for the institution. Copyright (C) 2010 S. Karger AG, Basel

Correlation between the Body Mass Index (BMI) of Pregnant Women and the Development of Hypotension after Spinal Anesthesia for Cesarean Section

Nani FS, Torres MLA - Correlation between the Body Mass Index (BMI) of Pregnant Women and the Development of Hypotension after Spinal Anesthesia for Cesarean Section. Background and objectives: Very few publications correlate hypotension in obese pregnant women, and especially morbidly obese, after spinal anesthesia for cesarean section. The objective of the present study was to evaluate the incidence of hypotension according to the BMI. Methods: Forty-nine patients with pregestational BMI below 25 kg.m(-2) were included in the Eutrophia group, and 51 patients with BMI >= 25 kg.m(-2) were included in the Overweight group. After spinal anesthesia, blood pressure, volume of crystalloid infused, and dose of vasopressors used until delivery were recorded. A fall in systolic blood pressure below 100 mmHg or 10% reduction of the initial systolic blood pressure (SBP) was considered as hypotension and it was corrected by the administration of vasopressors. Results: Episodes of hypotension were fewer in the Eutrophia group (5.89 +/- 0.53 vs. 7.80 +/- 0.66, p = 0.027), as well as the amount of crystalloid administered (1,298 +/- 413.6 mL vs. 1,539 +/- 460.0 mL; p = 0.007), and use of vasopressors (5.87 +/- 3.45 bolus vs. 7.70 +/- 4.46 bolus; p = 0.023). As for associated diseases, we observed higher incidence of diabetes among obese pregnant women (29.41% vs. 9.76%, RR 1.60, 95%CI: 1.15-2.22, p = 0.036), however, differences in the incidence of pregnancy-induced hypertension (PIN) were not observe between both groups (overweight: 21.57%, normal weight: 12.20%, RR 1.30, 95%CI: 0.88-1.94, p = 0.28). Conclusions: In the study sample, pregestational BMI >= 25 kg.m(-2) was a risk factor for hypotension after spinal anesthesia in patients undergoing cesarean section. The same group of patients required higher doses of vasopressors. Those results indicate that the anesthetic techniques in those patients should be improved to reduce the consequences of post-spinal anesthesia hypotension, both in pregnant women and fetuses.

Effect of phototherapy with low intensity laser on local and systemic immunomodulation following focal brain damage in rat

Brain injury is responsible for significant morbidity and mortality in trauma patients, but controversy still exists over therapeutic management for these patients. The objective of this study was to analyze the effect of phototherapy with low intensity lasers on local and systemic immunomodulation following cryogenic brain injury. Laser phototherapy was applied (or not-controls) immediately after cryogenic brain injury performed in 51 adult male Wistar rats. The animals were irradiated twice (3 h interval), with continuous diode laser (gallium-aluminum-arsenide (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP), 660 nm) in two points and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). The experimental groups were: Control (non-irradiated), RL3 (visible red laser/ 3 J/cm(2)), RL5 (visible red laser/5 J/cm(2)), IRL3 (infrared laser/ 3 J/cm(2)), IRL5 (infrared laser/5 J/cm(2)). The production of interleukin-1IL-1 beta (IL-1 beta), interleukin6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-alpha) was analyzed by enzyme immunoassay technique (ELISA) test in brain and blood samples. The IL-1 beta concentration in brain of the control group ;was significantly reduced in 24 h (p < 0.01). This reduction was also observed in the RL5 and IRL3 groups. The TNF-alpha and IL-6 concentrations increased significantly (p < 0.01 and p < 0.05, respectively) in the blood of all groups, except by the IRL3 group. The IL-6 levels in RL3 group were significantly smaller than in control group in both experimental times. IL-10 concentration was maintained stable in all groups in brain and blood. Under the conditions of this study, it is possible to conclude that the laser phototherapy can affect TNF-alpha, IL-1 beta and IL-6 levels in the brain and in circulation in the first 24 h following cryogenic brain injury. (C) 2009 Elsevier B.V. All rights reserved.

Classification model based on Raman spectra of selected morphological and biochemical tissue constituents for identification of atherosclerosis in human coronary arteries

This study presents the results of Raman spectroscopy applied to the classification of arterial tissue based on a simplified model using basal morphological and biochemical information extracted from the Raman spectra of arteries. The Raman spectrograph uses an 830-nm diode laser, imaging spectrograph, and a CCD camera. A total of 111 Raman spectra from arterial fragments were used to develop the model, and those spectra were compared to the spectra of collagen, fat cells, smooth muscle cells, calcification, and cholesterol in a linear fit model. Non-atherosclerotic (NA), fatty and fibrous-fatty atherosclerotic plaques (A) and calcified (C) arteries exhibited different spectral signatures related to different morphological structures presented in each tissue type. Discriminant analysis based on Mahalanobis distance was employed to classify the tissue type with respect to the relative intensity of each compound. This model was subsequently tested prospectively in a set of 55 spectra. The simplified diagnostic model showed that cholesterol, collagen, and adipocytes were the tissue constituents that gave the best classification capability and that those changes were correlated to histopathology. The simplified model, using spectra obtained from a few tissue morphological and biochemical constituents, showed feasibility by using a small amount of variables, easily extracted from gross samples.

Phototherapy Promotes Healing of Chronic Diabetic Leg Ulcers That Failed to Respond to Other Therapies

Objective: We tested the hypothesis that combined 660 and 890 nm LED phototherapy will promote healing of diabetic ulcers that failed to respond to other forms of treatment. Research Design and Methods: A double-blind randomized placebo controlled design was used to study 23 diabetic leg ulcers in two groups of 14 patients. Group one ulcers were cleaned, dressed with 1% silver sulfadiazine cream and treated with ""placebo"" phototherapy (<1.0 J cm(-2)) twice per week, using a Dynatron Solaris 705 (R) device. Group two ulcers were treated similarly but received 3 J cm(-2) dose. Results: At each of 15,30,45,60,75, and 90 days of healing, mean ulcer granulation and healing rates were significantly higher for group two than the ""placebo"" group (P < 0.02). While ""placebo"" treated ulcers worsened during the initial 30 days, group two ulcers healed rapidly; achieving 56% more granulation and 79.2% faster healing by day 30, and maintaining similarly higher rates of granulation and healing over the ""placebo"" group all through. By day 90, 58.3% of group two ulcers had healed fully and 75% had achieved 90-100% healing. In contrast, only one ""placebo"" treated ulcer healed fully by day 90; no other ulcer attained >90% healing. Conclusion: Combined 660 and 890 nm light promotes rapid granulation and healing of diabetic ulcers that failed to respond to other forms of treatment. Lasers Surg. Med. 41:433-441, 2009. (C) 2009 Wiley-Liss, Inc.

Glaucoma and Keratoprosthesis Surgery Role of Adjunctive Cyclophotocoagulation

Purpose: To evaluate the efficacy and safety of diode laser transscleral cyclophotocoagulation (DLTSC) to control intraocular pressure (IOP) in keratoprosthesis patients with uncontrolled glaucoma. Patients and Methods: Between 1993 and 2007, 18 eyes of 18 patients underwent DLTSC, either before (n = 3), during (n = I), or after (n = 14) keratoprosthesis surgery. Keratoprosthesis type 1 was used in 72%. All but one of these patients received an Ahmed Glaucoma Valve, either with or after the keratoprosthesis placement. Best-corrected visual acuity, IOP (assessed by digital palpation), number of medications, and complications were recorded preoperatively, at day 7, at 1, 3, and 6 months then every 6 months postoperatively. Results: Mean follow-tip was 26.6 +/- 19.6 months (mean +/- SD) and mean age was 50.1 +/- 15.6 years. Glaucoma was identified in 1 I eyes before keratoprosthesis surgery and in 7 eyes after. Mean postoperative IOP was significantly reduced at 6, 12, 24, 36, and 48 months after DLTSC. DLTSC was repeated in 6 eyes. At final visit, mean best-corrected visual acuity was not decreased and there were no statistically significant differences in the number of glaucoma medications. Two patients had complications after DLTSC: a conjunctival dehiscence and a fungal endophthalmitis. Conclusions: DLTSC has beneficial long-term effects in the control of IOP and can be considered in the management of keratoprosthesis patients with refractory glaucoma.

Experimental selective choriocapillaris photothrombosis using a modified indocyanine green formulation

Background: This in vivo study assessed and compared the effectiveness of an aqueous indocyanine green (ICG) formulation (R-ICG) and a lipid ICG formulation (L-ICG) in occluding the rabbit choriocapillaris, and determined the singlet oxygen quantum yields and aggregation properties of both formulations in vitro. Methods: Singlet oxygen production and aggregation were compared. The eye fundus of 30 albino rabbits was irradiated 0-15 min after dye injection using an 810 nm diode laser. Fluorescein angiography and light microscopy were used to evaluate the safety and efficacy of R-ICG and L-ICG. Results: L-ICG decreased the dimerisation constant and the tendency of ICG to form aggregates, and increased the efficiency of ICG in generating singlet oxygen (R-ICG, Phi Delta= 0.120 and L-ICG, Phi Delta= 0.210). Using a 10 mg/kg dose, choriocapillaris occlusion was achieved at a light dose of 35.8 J/cm(2) with L-ICG and 71.6 J/cm(2) with R-ICG with minimal damage to the neurosensory retina. Conclusion: Restrictions to the use of ICG in aqueous solution, low singlet oxygen quantum yields and high aggregation tendency, were overcome with L-ICG. The lower laser irradiance required to obtain choriocapillaris occlusion may suggest that L-ICG is a more potent and selective photosensitiser than R-ICG.

Genetic associations between carcass traits measured by real-time ultrasound and scrotal circumference and growth traits in Nelore cattle

The aim of the present study was to evaluate the genetic correlations among real-time ultrasound carcass, BW, and scrotal circumference (SC) traits in Nelore cattle. Carcass traits, measured by real-time ultrasound of the live animal, were recorded from 2002 to 2004 on 10 farms across 6 Brazilian states on 2,590 males and females ranging in age from 450 to 599 d. Ultrasound records of LM area (LMA) and backfat thickness (BF) were obtained from cross-sectional images between the 12th and 13th ribs, and rump fat thickness (RF) was measured between the hook and pin bones over the junction between gluteus medius and biceps femoris muscles. Also, BW (n = 22,778) and SC ( n = 5,695) were recorded on animals born between 1998 and 2003. The BW traits were 120, 210, 365, 450, and 550-d standardized BW (W120, W210, W365, W450, and W550), plus BW (WS) and hip height (HH) on the ultrasound scanning date. The SC traits were 365-, 450-, and 550-d standardized SC (SC365, SC450, and SC550). For the BW and SC traits, the database used was from the Nelore Breeding Program-Nelore Brazil. The genetic parameters were estimated with multivariate animal models and REML. Estimated genetic correlations between LMA and other traits were 0.06 (BF), -0.04 ( RF), 0.05 (HH), 0.58 (WS), 0.53 (W120), 0.62 (W210), 0.67 (W365), 0.64 ( W450 and W550), 0.28 (SC365), 0.24 (SC450), and 0.00 ( SC550). Estimated genetic correlations between BF and with other traits were 0.74 ( RF), -0.32 (HH), 0.19 (WS), -0.03 (W120), -0.10 (W210), 0.04 (W365), 0.01 (W450), 0.06 ( W550), 0.17 (SC365 and SC450), and -0.19 (SC550). Estimated genetic correlations between RF and other traits were -0.41 (HH), -0.09 (WS), -0.13 ( W120), -0.09 ( W210), -0.01 ( W365), 0.02 (W450), 0.03 (W550), 0.05 ( SC365), 0.11 ( SC450), and -0.18 (SC550). These estimates indicate that selection for carcass traits measured by real-time ultrasound should not cause antagonism in the genetic improvement of SC and BW traits. Also, selection to increase HH might decrease subcutaneous fat as correlated response. Therefore, to obtain animals suited to specific tropical production systems, carcass, BW, and SC traits should be considered in selection programs.

Effects of intrapulpal temperature change induced by visible light units on the metabolism of odontoblast-like cells

Purpose: To investigate the effects of intrapulpal temperature changes induced by a quartz tungsten halogen (QTH) and a light emitting diode (LED) curing units on the metabolism of odontoblast-like cells. Methods: Thirty-six 0.5 mm-thick dentin discs obtained from sound human teeth were randomly assigned into three groups: QTH, LED and no light (control). After placement of the dentin discs in pulp chamber devices, a thermistor was attached to the pulpal surface of each disc and the light sources were applied on the occlusal surface. After registering the temperature change, odontoblast-like cells MDPC-23 were seeded on the pulpal side of the discs and the curing lights were again applied. Cell metabolism was evaluated by the MTT assay and cell morphology was assessed by SEM. Results: In groups QTH and LED the intrapulpal temperature increased by 6.4 degrees C and 3.4 degrees C, respectively. The difference between both groups was statistically significant (Mann-Whitney; P< 0.05). QTH and LED reduced the cell metabolism by 36.4% and 33.4%, respectively. Regarding the cell metabolism, no statistically significant difference was observed between both groups (Mann-Whitney; P> 0.05). However, when compared to the control, only QTH significantly reduced the cell metabolism (Mann-Whitney; P< 0.05). It was concluded that the irradiance of 0.5 mm-thick human dentin discs with a QTH in comparison to a LED curing unit promoted a higher temperature rise, which propagates through the dentin negatively affecting the metabolism of the underlying cultured pulp cells. (Am J Dent 2009;22:151-156).

Genetic and environmental factors affecting ultrasound measures of longissimus muscle area and backfat thickness in Nelore cattle

The aim of the present study was to evaluate the genetic and environmental factors affecting records of longissimus muscle area (LMA) and back fat thickness (BF) obtained between the 12th and 13th ribs, and rump fat thickness (RF) between the hook and pin bones, measured by real-time ultrasound in Nelore cattle. Also, weight records of 22,778 animals born from 1998 to 2003, in ten farms across six Brazilian states were used. Carcass traits as measured by ultrasound of the live animal were recorded from 2002 to 2004 in 2590 males and females with ages varying from 450 to 599 days. Fixed models including farm, year and season of birth, sex and type of feed effects, and the covariates age of dam (AOD) and age of animal at measurement were used to study the effect of environmental factors on these traits. The genetic parameters for LMA, BF and RF were estimated with two and three-trait animal models with 120-day weights using a restricted maximum likelihood method. All environmental effects significantly affected carcass traits, with the exception of year of birth for BF and RF and AOD for LMA. The heritability estimates for LMA, BF and RF were 0.35, 0.51 and 0.39, respectively. Standard errors obtained in one-trait analyses were from 0.07 to 0.09. Genetic correlation estimates between LMA and the two traits of subcutaneous fat were low (close to zero) and 0.74 between BF and RF, indicating that the selection for LMA should not cause antagonism in the genetic improvement of subcutaneous fat measured by real-time ultrasound. (C) 2007 Elsevier B.V. All fights reserved.

Mast cell concentration in the wound healing process of incisions made by different instruments

The aim of this study was to compare the concentration of mast cells (MCs) in the healing process of incisions. Thirty rats were submitted to six linear incisions each, performed in the dorsal skin by carbon dioxide (CO(2)) and diode lasers, electrocautery and conventional scalpel. The animals were euthanized at intervals of 0 h, 24 h, 48 h, 72 h, 7 days and 14 days after the incisions had been made. Histological sections were obtained and stained with toluidine blue for identification of MCs, which were manually counted by conventional microscopy in 20 microscopic fields in the border of the incision, near the granulation tissue, or in the area of new collagen formation, depending on intervals. The concentration of MCs was significantly higher in the wounds made by scalpel than in those made by other techniques at 48 h and 72 h. After 72 h the number of MCs was also significantly higher after electrocautery than after incisions made by 4 W CO(2) laser. On days 7 and 14, there was no significant difference in the MC count among the different types of incisions. In summary, the MC concentration varied after different surgical incisions at early phases of wound healing. At the end of the healing process, however, there were similar MC concentrations around the incisions, suggesting that, in standard incisions in the surgical techniques studied, the wound healing process ultimately occurred in a similar pattern.

Laser phototherapy effect on protein metabolism parameters of rat salivary glands

The aim of this study was to evaluate the effects of infrared diode laser phototherapy (LP) on tissues of the submandibular gland (SMG) and parotid gland (PG). Wistar rats were randomly divided into experimental (A and B) and control (C) groups. A diode laser, 808 nm wavelength, in continuous wave mode, was applied to the PG, SMG and sublingual gland in the experimental groups on two consecutive days. The doses were 4 J/cm(2) and 8 J/cm(2), and total energy was 7 J and 14 J, respectively. The power output (500 mW) and power density (277 mW/cm(2)) were the same for both experimental groups. In order to visualize the area irradiated by the infrared laser, we used a red pilot beam (650 nm) with 3 mW maximum power for the experimental groups. For the control group, the red pilot beam was the only device used. The SMG and PG were removed after 1 week of the first irradiation. Total protein concentration, amylase, peroxidase, catalase and lactate dehydrogenase assays were performed, as well as histological analysis. Statistical tests revealed significant increase in the total protein concentration for groups A and B in the parotid glands (P < 0.05). Based on the results of this study, LP altered the total protein concentration in rats` parotid glands.

Stem cell proliferation under low intensity laser irradiation: A preliminary study

Background and Objectives: Phototherapy with low intensity laser irradiation has shown to be effective in promoting the proliferation of different cells. The aim of this in vitro study was to evaluate the potential effect of laser phototherapy (660 nm) on human dental pulp stem cell (hDPSC) proliferation. Study Design/Materials and Methods: The hDPSC cell strain was used. Cells cultured under nutritional deficit (10% FBS) were either irradiated or not (control) using two different power settings (20 mW/6 seconds to 40 mW/3 seconds), with an InGaAIP diode laser. The cell growth was indirectly assessed by measuring the cell mitochondrial activity through the MTT reduction-based cytotoxicity assay. Results: The group irradiated with the 20 mW setting presented significantly higher MTT activity at 72 hours than the other two groups (negative control-10% FBSand lased 40 mW with 3 seconds exposure time). After 24 hours of the first irradiation, cultures grown under nutritional deficit (10% FBS) and irradiated presented significantly higher viable cells than the non-irradiated cultures grown under the same nutritional conditions. Conclusions: Under the conditions of this study it was possible to conclude that the cell strain hDPSC responds positively to laser phototherapy by improving the cell growth when cultured under nutritional deficit conditions. Thus, the association of laser phototherapy and hDPSC cells could be of importance for future tissue engineering and regenerative medicine. Moreover, it opens the possibility of using laser phototherapy for improving the cell growth of other types of stem cells.

Effect of laser phototherapy on the release of fibroblast growth factors by human gingival fibroblasts

The effects of laser phototherapy on the release of growth factors by human gingival fibroblasts were studied in vitro. Cells from a primary culture were irradiated twice (6 h interval), with continuous diode laser [gallium-aluminum-arsenium (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP),_660 nm] in punctual and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). Positive [10% fetal bovine serum (FBS)] and negative (1%FBS) controls were not irradiated. Production of keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF) was quantified by enzyme-linked immunosorbent assay (ELISA). The data were statistically compared by analysis of variance (ANOVA) followed by Tukey`s test (P a parts per thousand currency signaEuro parts per thousand 0.05). The characterization of the cell line indicated a mesenchymal nature. KGF release was similar in all groups, while that of bFGF was significantly greater (1.49-times) in groups treated with infra-red laser. It was concluded that increased production of bFGF could be one of the mechanisms by which infra-red laser stimulates wound healing.